The following description relates to vehicle steering columns and, more particularly, to a redundant gear assembly for such steering columns.
Electrically actuated or electrically assisted steering systems provide power assist to a steering assembly. A controller receives an input signal and commands an electric motor to drive a gear arrangement to provide assistance to a user by lessening the input torque required to perform various steering functions. Many of the gear arrangements do not include redundancy. If a gear tooth breaks, the vehicle reverts to manual steering. As steering loads increase, manual steering may be too difficult for some drivers. Furthermore, manual control is not available in steer by wire applications, as there may not be a physical connection between the steering wheel and the road wheels. In an effort to increase safety, many automobile manufacturers are requesting redundancies in many vehicle applications, including steering systems.